Bursitis is an inflammation or irritation of the bursae (plural of “bursa”). The bursae are fluid-filled sacs in the joints that decrease friction and provide a cushion between bones, muscles, and skin.

Bursitis can be acute (often as a result of an injury or infection) or chronic (for example, following a long period of repetitive use or motion). It can affect almost any joint in the body, although some are more commonly affected than others.

BURSITIS CAUSES

Causes of bursitis include:

●Injury, such as from a fall or hit

●Prolonged pressure, which can result from kneeling, sitting, or leaning on a particular joint for a long period

●Strain or overuse from repeating the same motion many times

●Joint stress from an abnormal gait; for example, walking unevenly because one leg is shorter than the other

●Gout or other crystal diseases

●Certain types of arthritis, like rheumatoid arthritis or psoriatic arthritis

●Infection resulting from bacteria entering the body through a cut or scrape in the skin

BURSITIS SYMPTOMS

Common symptoms of bursitis include pain and swelling in the affected joint. Visible swelling is more common in bursae that are closer to the surface of the skin (such as those around the elbows, kneecaps, and heels), and less common in deeper areas (such as the shoulders, hips, and inner knees).

In acute bursitis, there is often pain directly over the affected bursa; active motion (when the patient moves or bends the joint) also causes pain. People with chronic bursitis are more likely to have swelling, often with minimal pain. They may have limited range of motion due to avoiding moving the joint and surrounding muscles.

Bursitis caused by an infection is called “septic bursitis.” Symptoms may include pain, swelling, warmth, and redness around the affected joint. Fever may also be present. This is a potentially serious condition, since infection can spread to nearby joints or the blood.

Specific symptoms vary depending on the area that is affected. (See 'Types of bursitis' below.)

If infection or crystal disease (for example, gout) is suspected, your doctor may use a syringe and needle to remove a sample of fluid from the affected bursa. This is called “aspiration.” The fluid can then be examined under a microscope for crystals, bacteria, and white blood cells.

Imaging (such as radiograph, MRI, or ultrasound) is not usually needed to diagnose bursitis. However, it can help in some situations, such as when other problems (for example, a tear in the cartilage or ligament) need to be ruled out quickly. It can also be useful if your doctor needs to remove fluid from a bursa near other areas that could be injured, such as nerves or blood vessels. Imaging can allow the doctor to see where the needle is going.

TYPES OF BURSITIS

Bursitis can affect many different areas of the body. The exact symptoms and preferred treatments depend on the location as well as the cause.

Shoulder (subacromial bursitis) — Shoulder bursitis causes pain in the shoulder and outside of the upper arm (figure 1). Pain is often present at rest but increases with movement of the arm, especially with lifting the arms above the head; it also often interrupts sleep. It can be difficult to differentiate shoulder bursitis from other issues such as a rotator cuff tear or tendinitis.

Upper back (scapulothoracic bursitis) — Upper back bursitis affects the space between the scapula (shoulder blade) and ribs, and can cause pain or a popping sensation. Reaching the arms overhead or doing pushups can make pain worse.

Elbow (olecranon bursitis) — Elbow bursitis usually causes a visible swelling at the tip of the elbow, like a golf ball. It can result from injury, infection, crystals (gout), or rheumatoid arthritis. It usually causes pain when the elbow is flexed, but not extended. The elbow often extends fully without discomfort.

Pelvis (ischial bursitis) — Pelvic bursitis has also been referred to as “weaver’s bottom” or “tailor’s bottom,” since it is often caused by prolonged sitting on hard surfaces. It causes pain in the lower buttocks that is aggravated by sitting (figure 2); pain may disappear when the person stands.

Hip

Greater trochanteric pain syndrome (formerly called trochanteric bursitis) — The greater trochanteric bursa is located in the upper outer part of the femur (thigh bone) (figure 2). Bursitis in this area is usually associated with inflammation of nearby tendons and can cause pain while lying or sleeping on the affected side of the body. People with greater trochanteric pain syndrome also tend to have pain when extending the leg to walk, but not while standing still. Symptoms can be aggravated by an abnormal gait, due to uneven stress on the hips. There are many contributing factors, including chronic back pain, contralateral knee pain (knee pain on the opposite side of the body from the bursitis), different leg lengths, and being overweight.

Iliopsoas bursitis — The iliopsoas bursa is deep in the front of the hip. This type of bursitis causes pain in the groin area, particularly when the hip is flexed against resistance. It can result from arthritis in the area, overuse (for example, excessive running), or injury. Because symptoms are similar to those of other hip problems (for example, problems with the bone or cartilage), imaging tests are often required to confirm the diagnosis. Infection in the psoas muscle (psoas abscess) can have similar symptoms. (The psoas muscle runs from the spine to the femur, and is used to flex the hip.)

Knee

Prepatellar and infrapatellar bursitis — The prepatellar bursa is located at the front of the knee, on top of the patella (kneecap) (figure 3); the infrapatellar bursa is below this. Bursitis in these areas can result from recurrent injury to the knee, and is often seen in people who frequently kneel (prepatellar bursitis has been referred to as “housemaid’s knee” or “nun’s knee”). It can also happen as a result of infection, gout, or rheumatoid arthritis. Swelling occurs within the bursa, not in the knee joint itself. People with prepatellar and infrapatellar bursitis usually feel more comfortable lying down with the knee extended, while people with swelling within the true knee joint tend to feel better lying down with the knee bent.

MCL bursitis — The medial collateral ligament (MCL) is located on the inner side of the knee, and connects the femur (thigh bone) to the tibia (shin bone) (figure 4). Bursitis in this area can cause pain and tenderness, but doesn’t usually involve swelling. It must be differentiated from an injury or tear to the MCL or meniscus (the cartilage in the knee).

Pes anserinus pain syndrome — The anserine bursa is located about two inches below the top of the tibia (shin bone), on the inner side of the knee. Pes anserinus pain syndrome (formerly referred to as anserine bursitis) causes pain on the inner side of the knee, which tends to come on abruptly, often during the night. It is common in people with arthritis of the knee; it can also result from an uneven gait (for example, walking with a limp or while favoring one leg over time), or from flat feet.

Heel (retrocalcaneal bursitis) — The retrocalcaneal bursa is between the heel bone and the Achilles tendon, which connects the heel to the calf muscle. It normally serves as a cushion to absorb impact when walking. Retrocalcaneal bursitis can cause pain and swelling in the area. It can be easily confused with tendinitis (inflammation of the Achilles tendon).

Protecting the joints — It is important to protect the affected joints in order to help the bursae to heal, and to prevent the bursitis from getting worse or recurring. Examples of joint protection include:

●Avoiding or modifying activities that cause pain

●The use of pads or cushions for people who have to kneel or sit frequently

●Modifying footwear to reduce pressure on the back of the heel (eg, cutting a “V”-shaped groove into the back of a shoe; using a pad inside the shoe to lift the heel)

●Custom-fitted devices worn over the elbows to protect them and prevent fluid from building up again

Other measures — Ice can help relieve pain, particularly for bursitis affecting superficial areas like the elbow, kneecap, and heel. Heat (eg, a heating pad) may be more effective for deeper forms of bursitis, such as the hip, shoulder, or inner knee.

In many cases, physical therapy can help treat symptoms of bursitis and prevent future recurrence. The optimal exercises depend on the type and severity of bursitis, but may involve stretching, strengthening, or working to improve (and maintain) range of motion.

Rarely, surgery is required to remove all or part of the affected bursa.

Treating infection — Septic bursitis is treated with antibiotics. The choice of which antibiotic to use, and for how long, is based on the type and severity of infection. For mild cases, a few weeks of oral antibiotics may be enough; for more severe infection, intravenous (IV) antibiotics (given in the hospital) may be required.

It is also often necessary to drain infected fluid using a needle. This is done in a doctor’s office, usually several times, until the infection has resolved.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

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